This application is based on Patent Application Nos. 2000-26110, 2000-26111 and 2000-26116 filed Feb. 3, 2000 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to an ink-transport system to be used in an ink-jet printing apparatus, an ink-replacement method, an ink-supply system, and an ink-jet printing apparatus. Especially, the present invention relates to a technology suitable for frequently changing various kinds of inks depending on the type of printing media, printing characteristics of the printing apparatus, and so on.
2. Description of the Prior Art
The ink-jet printing system is carried out by causing fine droplets of inks to fly and adhere to a printing medium such as paper based on various operational principles, to print images, characters, or the like, thereby enabling printing with low noise at a high speed. The ink-jet printing system has advantages such as facilitation of multicolor printing and is characterized by a high degree of freedom for recordable patterns, elimination of the necessity of development or fixation, and others. Thus, printing apparatuses based on this system method have been rapidly spread in various fields including that of data processing to accommodate various images and print media.
In addition, images formed by means of the multicolor ink-jet printing system can easily stand comparison with multicolor printing based on the plate making system or photographic printing based on the color photographing system. The multicolor ink-jet printing system enables images to be produced more inexpensively than normal multicolor printing or photographic printing if a small number of copies are particularly to be printed and is thus widely used in the field of full-color image printing. There are two types of the conventional ink-jet printing apparatuses. One is that an ink tank portion and an printing head portion are integrally formed together so that they cannot be removed from each other. The other is that an ink tank portion and a printing head portion are integrally are independently formed so that they can be removed from each other. In the former (i.e., the integral type printing apparatuses), they can be further grouped into additional types to cope with a shortage of ink. That is, one is that both the ink tank and the printing head are replaced with the new ones, respectively; and the other is that a shortage of ink is compensated by refilling the ink tank with ink from the outside. In the latter (i.e., the printing apparatus with the ink tank to be detached from the printing head), the ink tank can be replaced with the new one filled with ink when the ink tank becomes almost empty.
For the both cases, however, the ink tank is refilled with the same type of ink as one used before in the printing apparatus.
To accommodate wider applications of the ink-jet printing system and enable the recent improvement of printing characteristics such as an increased printing speed, an improved definition, and full color printing, efforts are being made to improve the printing apparatus and method. Characteristics required to achieve wider applications of the ink-jet printing system and improve the printing characteristics include, for example, a high density of printed ink dots, bright and clear color tones, fast ink absorption, prevention of outflow or bleeding of inks despite overlapping ink dots, and spread of ink dots with appropriate bleeding.
It is known that these characteristics are realized not only by the printing apparatus and method but also by improving inks or printing media used for printing.
For example, it is known that a coated paper is used as a printing medium due to ink absorptivity and fixability achieved thereby. The coated paper comprises, for example, a silicon pigment such as silica, or an absorbing polymer including a resin such as colloidal silica, polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene oxide-isocyanate crosslinked material, or an acrylic polymer having a carboxyl group, or an aluminum-based pigment such as alumina hydrated compound or aluminum oxide, which is each coated on a paper, a film, a cloth, or the like together with an aqueous binder or the like. On the other hand, inks have their permeability adjusted by means of a surface-active agent or the like contained therein.
To accommodate the improvement of the printing characteristics, however, an optimal combination of printing media and inks which can realize these characteristics is more preferably selected by individually selecting printing media or inks depending on each of the characteristics. This is because the inks and the printing media show each of the characteristics through their mutual relationship.
In this case, to specifically realize the optical combination of the printing media and the inks in an ink-jet printing apparatus, configurations and operations are required which replace or install the printing media or the inks depending on a combination of printing media and inks. Additionally, an operation is required for setting printing conditions on, for example, a host computer; for example, a printing mode must be set depending on such a combination. That is, it is cumbersome to carry out the above operations or setting operations each time the combination is switched. It is also difficult for a user to obtain the optimal combination.
In this respect, an official gazette of Japanese Patent Application Laying-open No. 11-254700 (1999) discloses a media cartridge to be removably mounted on a printing apparatus. The media cartridge has a single-piece construction provided as a combination of: a cassette member on which sheets of printing media are mounted; and an ink tank or a waste ink tank for holding waste ink. The printing apparatus recognizes the presence of the media cartridge removably mounted thereon and automatically defines its printing mode with reference to the types of the printing medium and the ink. Therefore, it allows an appropriate printing control that depends on the above combination of the printing medium and the ink.
The printing apparatus using the media cartridge such as one disclosed in Japanese Patent Application Laying-open No. 11-254700 (1999) is suitable for forming an image of high quality on a sheet of high-priced printing medium. In other words, the configuration of the printing apparatus avoids a mismatched combination of printing medium and ink, so that an image formation can be performed simply and easily without making any mistakes. Therefore, the above printing apparatus has been valued as being extremely useful for forming various kinds of images in low volume.
In the above printing apparatus, however, ink has been frequently changed from one kind to another in accordance with the replacement of the media cartridge with the new one. In this case, there is a necessity that ink in the printing head is also changed from one kind to another, so that the printing apparatus can be expensive as a whole if the printing heads are prepared to correspond with various kinds of inks.
For replacing the media cartridge with the new one, there is a need to drain ink out of both the ink tank and the head and to refill them with ink from a new media pack to be replaced. In this case, an insufficient drain of ink may be caused if the ink is drained from ink ejection ports of the head by applying pressure to the inside of the ink tank. If the ink to be supplied by the media cartridge after the replacement has a color different from that of the prior cartridge, ink to be ejected from the printing head may be of a color mixture with the prior ink. It causes a problem that the printing head ejects ink having a color different from the desired one.
If the printing head and the ink tank are filled with acid ink even though they had been filled with ink of an alkali-soluble dye, it facilitates coagulation or precipitation of the dye out of the ink. If so-called pigment ink prepared by dispersing pigment particles into a coloring material is replaced with another type of the pigment ink, the dispersing state becomes worse by the differences in their properties such as pH values, concentrations, and solvent compositions and such a state facilitates coagulation of pigment particles. As a result of causing precipitates or agglomerates in the ink, such undesired materials may block ink ejection ports of the printing head or adhere to a face surface (i.e., a surface of the printing head on which the ink ejection ports are formed). Consequently, any deleterious effect can be produced on the ability to eject ink droplets from each ink ejection port with stability. Furthermore, if the ink ejection ports tend to be closed as the printing head has not been used for a long time, there is a necessity to drain ink from both the ink tank and the head.
In summary, therefore, the conventional ink-supplying system for an ink-jet printing apparatus has the problems in which:
a high quality image cannot be obtained because of using ink manufactured specifically for ordinary paper and held in the media cartridge;
the price of the printing apparatus as a whole is considerably increased because of using a printing head designed specifically for each of different ink variations or using a disposable head; and
different ink colors may be mixed after replacing ink in both the ink tank and the head with ink of different color.
In the conventional printing apparatus for making a high quality image, there may be cases where various kinds of inks are used in addition to basic inks of three primary colors. The inks may include special inks, for example light-colored ink having a low concentration and dark-colored ink having a high concentration. If the various kinds of inks are used, variations in the amount of each ink consumed can be easily occurred. In this case, there may be the need for the supply of only one kind of ink. In this case, by the way, there is a limit to the amount of ink in an ink-reserving chamber as an ink supply source equipped in the ink media pack mentioned above can store. In addition, an ink tank mounted on a carriage of the printing apparatus is replenished with only a small amount of ink. Therefore, the number of occurrences in requesting the supply of such specific ink will be increased.
In the conventional ink-introducing system, however, each of the ink tanks mounted on a carriage cannot be replenished with ink, independently. The user is forced to replenish all of the ink tanks with ink at the same time. Therefore, user does not introduce ink to only specific ink tank.
More specifically, the conventional ink-jet printing apparatus comprises a plurality of ink-storage portions in an ink tank, where ink-introducing openings are respectively formed on the top faces of ink-storage portion and arranged in a line. In addition, a plurality of ink-introducing needles to be removably inserted into the respective ink-introducing openings is arranged in a line parallel to the line of openings. For replenishing the ink-storage portions with ink, each ink-introducing needle is inserted into the corresponding ink-introducing opening. Then, the ink-introducing needles concurrently replenish their respective ink-introducing openings with ink. Therefore, the ink-storage portion with a sufficient amount of ink remained forcefully receives the supply of ink, so that the amount of ink to be supplied from each ink-introducing needle should be adjusted to the ink consumption amount of ink consumed minimum amount. As a result, there are very serious problems that a sufficient amount of ink cannot be supplied to the target ink-storage portion and the supply of ink should be repeated at very close intervals.
As described above, in Japanese Patent Application Laying-open No.11-254700 (1999) mentioned above describes the media cartridge provided as a combination of the cassette holding printing medium and the ink tank. However, it does not specify the configuration of the printing apparatus with consideration given to make the printing apparatus as compact as possible and to facilitate handling of the cartridge, and also given to a particular use thereof.
Furthermore, the above document does not teach any combination of printing medium and ink that achieves the desired printing properties of the printing apparatus with consideration given to raw materials and compositions of both the printing medium and the ink. In the above document, if plural sheets of ordinary paper is set as the printing medium in the cartridge, a treatment liquid that makes a dye in ink insoluble, black, yellow, magenta, and cyan ink are set as ink in the ink tank. In the above document, however, if plural sheets of coated or glossy paper or overhead transparency films (OHP sheets) as the printing media in the cartridge, black, yellow, magenta, and cyan ink can be set as ink in the ink tank with the exception of the treatment liquid. The reason is considering the fact that image quality could be declined if the treatment liquid was applied to the surface of coated paper or the like with coating of an ink-acceptable layer. For setting a mode of photographic-quality image formation, the above document describes the ink setting, for example, consisting of dark black, light black, dark yellow, light yellow, dark magenta, light magenta, dark cyan, and light cyan.
Accordingly, Japanese Patent Application Laying-open No. 11-254700 (1999) described above discloses nothing but the media cartridge designed in combination with ink to be selected from several kinds of ink which can be easily distinguished by the user in accordance with the printing medium or printing mode. On the other hand, there is an appropriate combination of printing medium and ink in terms of imparting a desired color on that medium. The appropriate ink composition varies as the row material or composition of the printing medium varies in spite of similar appearance among the medium at first glance. In this case, however, it is close to impossible that the user selects an appropriate one from the various possible combinations.
Another problem is that many ink-jet printing apparatuses presently known in the art have been designed to have their own printing properties which are more or less directed to specific requirements, respectively. Therefore, it is comparatively difficult to meet the needs for various properties described above.
One of the characteristics of the printing head as one that defines the printing properties is the longevity of the printing head in itself. If the printing head is used very often, it is required to further increase the durability of the printing head. In addition, one of the characteristics of the ink as one that defines the printing properties is to be easily removed from a nozzle by means of a so-called recovery movement or the like in spite of after being left for the comparatively long term. Furthermore, another characteristic of the ink as one that defines the printing properties is to have its own formula color, or the like which is hardly changed or tarnished. The printing properties of the conventional ink-jet printing apparatus are limited by the factors described above, such that if the manufacturer attempts to provide an ink-jet printing apparatus having all of the printing properties, there are tendencies to upsize the system and to rise the cost of manufacturing the system. Therefore, the manufacturer of ink-jet printer or the like restricts the printing properties of each type of printers so as to specifically meet at least one of user demands, such as one that makes a high quality image or one to be used at a low or high temperature. In the present circumstances, the manufacturer limits the abilities of the printers within a certain range to manufacture and sold them in the market to fill the main current of demands on printers. Therefore, if the user having an ink-jet printer with a certain printing property xe2x80x9cAxe2x80x9d wants to print an image using another printing property xe2x80x9cBxe2x80x9d, there is a limit to what the printer can do even if the special mode is set up to cope with the printing property xe2x80x9cBxe2x80x9d. For making compensation for lack of the printing property xe2x80x9cBxe2x80x9d to a satisfactory degree, there is a problem that the user is forced to consider purchase of an additional printer having the printing property xe2x80x9cBxe2x80x9d.
One of the objects of the present invention is to provide a technology that offer a cheap configuration of the ink-jet printing apparatus to cope with frequent changes in the types of ink to be used without causing any trouble in the properties of ink ejection.
Another object of the present invention is to provide a technology that allows an application of an ink media pack more effectively, where both printing medium and ink are integrally housed in the ink media pack by appropriately making a combination of them.
A further object of the present invention is to provide an ink-supply system that allows that the required and enough amount of ink is independently supplied to each ink-storage portion of the ink tank.
A still further object of the present invention is to provide an ink-jet printing apparatus that realizes various printing properties thereof by its simple configuration, or more specifically to provide an ink-jet printing apparatus on which an easy-to-handle ink media pack with an integral combination of ink and printing medium or an ink tank is removably mounted to avoid a profligate use of ink and to avoid a profligate work of ink replacement.
In the first aspect of the present invention, there is provided an ink-transport system for transporting ink to a printing head capable of ejecting ink, comprising:
a first selector means for selecting one state for a passage that communicates with the printing head from a state in which the passage opens to atmosphere and a state in which the passage communicates with an ink storage container that stores ink to be supplied to the printing head; and
s second selector means for selecting one state for the printing head from a state in which the printing head is under reduced pressure and a state in which the printing head communicates to atmosphere.
In a second aspect of the present invention, there is provided an ink-transport system for transporting ink to a printing head capable of ejecting ink, wherein
the printing head comprises: an ink ejecting portion for ejecting ink;
a sub tank portion made of a flexible material that stores ink and communicates with the ink ejecting portion;
a first open/close mechanism for allowing a communication between the inside of the sub tank portion and the outside; and
a second open/close mechanism for allowing a communication between a space portion housing the sub tank portion and the outside, and
further comprises:
an atmospheric pressure introducing means which is able to introduce the atmospheric pressure into the inside of the sub tank;
an ink supply means which is able to supply ink from an ink supplying source to the inside of the sub tank;
an ink draining means which is able to drain ink from the inside of the sub tank through the ink ejecting portion; and
a pressure regulating means which is able to regulate a reduced pressure in the space portion.
In a third aspect of the present invention, there is provided a method for replacing ink to be ejected from a printing head, in an ink-jet printing apparatus that performs a printing movement by discharging ink stored in an ink reserving portion through the printing head, comprising the steps of:
introducing air into the ink reserving portion;
draining ink and air from the ink reserving portion to the outside; and
introducing ink into the ink reserving portion from which ink and air were drained at the draining step.
In a fourth aspect of the present invention, there is provided an ink-jet printing apparatus comprising the ink-transport system of the first or second aspect of the present invention.
In a fifth aspect of the present invention, there is provided an ink-jet printing apparatus comprising means for executing each step in the ink replacement method of the third aspect of the present invention.
In a sixth aspect of the present invention, there is provided an ink-supply system for supplying ink from a plurality of main ink tanks to their respective sub ink tanks that communicate with printing head for ejecting ink, comprising:
a plurality of ink receiving portions that are respectively communicated with the plurality of sub ink tanks, which are arranged on one of two opposite parts capable of relative movements; and
a plurality of ink supplying portions to be respectively paired with the plurality of ink reserving portions, which are respectively communicated with the plurality of main ink tanks, and which are arranged on the other of two opposite parts, wherein the ink receiving portion and the ink supplying portion of each pair is able to connect together when the two opposite parts relatively move to their respective predetermined opposite positions, and
the plurality of ink receiving portions and the plurality of ink supplying portions are positioned by the relative movements of the two opposite parts to their respective predetermined opposite positions that permit a predetermined number of connecting pairs at a time.
In the seventh aspect of the present invention, there is provided an ink-jet printing apparatus comprising an ink-supply system of the sixth aspect of the present invention.
In an eighth aspect of the present invention, there is provided an ink-jet printing apparatus comprising a sub ink tank capable of receiving a supply of ink from an ink tank which can be removably mounted on a body and allowing an image printing on a printing medium using ink in the sub ink tank, comprising:
an ink replacement means that allows an ink replacement movement for replacing ink in the sub ink tank with ink in the ink tank; and
a control means for controlling the ink replacement means in accordance with a first ink information on the type of ink in the sub ink tank and a second ink information on the type of ink to be used in the printing movement.
According to the present invention, a same printing head and a same ink-storage portion can be always used irrespective of frequent change for the types of ink in accordance with change for the types of printing medium. Therefore, there is no need to prepare a printing head designed specifically for each type of ink and to replace the printing head with the new one every time the ink media pack is replaced with the new one. Consequently, the replacement of ink with another one can be easily and perfectly performed and also the cost to be required for the replacement of ink can be extensively decreased.
If the so-called ink media pack comprising a combination of printing medium and ink is mounted on the ink-jet printing apparatus, there is no need to replace the printing head when the ink media pack is replaced with another type one. Consequently, the ink media pack can be easily handled, compared with the conventional one, so that the utility of the media pack can be extensively increased.
According to the present invention, furthermore, a plurality of ink-reserving chambers is equipped in the ink tank mounted on the carriage. These ink-reserving chambers receive the supplies of ink in independent from each other. Therefore, the required and enough amount of ink can be easily and perfectly introduced into each ink-reserving chamber even if the amount of ink remained in each chamber is different from the others.
In the ink-jet printing apparatus of the present invention, when the ink tank or the integral-type pack comprising a combination of printing medium and ink is replaced with the new one, ink in the ink sub tank is not replaced with ink in the ink tank or the integral-type pack. In this case, the replacement of ink is only performed on the ink sub tank that requires such a replacement in accordance with an ink information pertaining to the variations of ink. Therefore, it eliminates a waste of ink.
By performing such an operation of ink replacement just before the printing movement, the replacement of ink can be only performed on the ink sub tank that requires the ink replacement by appropriately recognizing such a sub tank. The replacement of ink is not performed even if the ink tank or the integral-type pack is replaced with the new one several times. As a result, it eliminates a waste of ink. Eventually, furthermore, the duration of printing movement can be decreased as a whole by shortening the time required for the operation of ink replacement because the ink replacement is only performed on the ink sub tank that requires such an ink replacement.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.